1. Field of the Invention
The present invention relates to a motorized window treatment, and more particularly, to a motorized roller shade system for winding receipt of a thin, pleated fabric around a roller tube.
2. Description of the Related Art
Typical window treatments, such as, for example, roller shades, draperies, roman shades, and venetian blinds, are mounted in front of windows to prevent sunlight from entering a space and to provide privacy. A roller shade includes a flexible shade fabric wound onto an elongated roller tube. The flexible shade fabric typically includes a weighted hem bar at a lower end of the shade fabric, such that the shade fabric hangs in front of the window. Motorized roller shades include a drive system engaging the roller tube to provide for tube rotation, such that the lower end of the shade fabric can be raised and lowered (i.e., moved in a vertical direction) by rotating the roller tube.
Many thin and flexible fabrics, such as, for example, silk, are not suitable for use with prior art roller shades, since the thin fabrics tend to not hang flat and tend not to roll up evenly on the roller tube. Therefore, such thin fabrics are typically laminated to a stiffer backing to be wound about a roller tube. While the lamination allows the thin fabrics to be used with a roller shade, the thin fabrics loose their soft look and feel as a result of this process.
Prior art draperies have allowed for horizontal movement of a suspended pleated drapery fabric covering a window or other opening. These prior art draperies have required additional space to be provided on the sides of the window or opening to hold the drapery fabric when the drapery is fully open. This prevents the draperies from being used to cover windows where there is little space at the sides of the windows.
Accordingly, there is a need for a roller shade system having a thin, flexible shade fabric that allows the shade fabric to hang with pleats and to be wrapped around a roller tube (i.e., moved in a vertical direction).